Space Access Update is Space Access Society's when-there's-news publication. Space Access Society's goal is to promote affordable access to space for all, period. We believe in concentrating our limited resources at whatever point looks like yielding maximum progress toward this goal.
For the moment, our main focus is on supporting the government's "SSRT" (Single Stage Rocket Technology) program, DC-X and its recently funded followon, SX-2. Space Access Update is thus for the moment largely about the technology and politics of DC-X and SX-2, though we also cover the subject of reusable SSTO (Single Stage To Orbit) policy in general.
We anticipate a change of focus soon if all goes well. Once SX-2 startup is (with your help!) assured, we plan to begin working on establishment of a healthy second X-rocket development track at NASA, and on getting development of suitable engines started for the fully reusable orbital transports that should come after SX-2 and NASA's X-rocket.
With luck and hard work, we should see fully reusable SSTO testbeds flying to orbit toward the end of this decade, with production ships a-building shortly thereafter. Join us and help us make this happen.
Henry Vanderbilt, Editor, Space Access Update
[For more info on Space Access Society or on the DC-X/SSTO video we have for sale, write us at 4855 E Warner Rd #24-150, Phoenix AZ 85044, or email hvanderbilt@bix.com. Please forgive any delay in our reply; we're a couple weeks behind in answering non life-or-death email right now.]
SAS members got a note from us, and the rest of you likely have heard elsewhere that DC-X's first flight since the long layoff (on Monday June 20th) went just about as expected, taking off with a full propellant load for the first time, reaching a maximum altitude of 2850 feet and a maximum angle of attack of 70 degrees, and staying aloft for just under 136 seconds. The previous maximum flight duration was 72 seconds.
The second flight of the new series was scheduled for a week later, Monday June 27th, and was to be the first half of a three-day turnaround test, the second half being scheduled for Thursday June 30th. Two additional flights were tentatively scheduled for mid-July.
Well, that schedule is down the tubes now. DC-X is pretty much OK, but as you've all likely heard from the early reports, things didn't go exactly as planned last Monday. Future flight dates are very much up in the air right now. More on this in a bit. The good news, of course, is that DC-X did manage to land essentially intact, further proof that aircraft-style operations are possible for reusable rockets.
This second new-series flight was open to the press and to a limited number of invitees. Yours truly was there, lugging a rented camcorder.
The flight was scheduled for 9 am on Monday, June 27th. The ship was ready to go well ahead of time; the pacing item for flight became the test range timeslot opening up. The go-ahead came from the range a little past 8:30 am, and the count restarted at just over minus two minutes, everything normal, with a light wind out of the north at about five knots.
The short version: There was some sort of explosion right around the moment of engine startup, splitting open the graphite/epoxy aeroshell on the south side of the vehicle. The vehicle systems all still showed as OK in the FOCC (Flight Operations Control Center trailer) displays; the pilot, Pete Conrad, went ahead with the flight.
As the DC-X rose out of the cloud of dust and vapor from engine startup, however, yard-square pieces of aeroshell began to fall off every second or two, alerting the crowd that something was wrong. Close-up views from the pad area TV cameras apparently showed a big hole in the vehicle side; Conrad was told of this and decided to switch over to the autoland program, an abort mode designed to cancel all maneuvers in progress then bring the vehicle straight down to a landing as quickly as possible.
(The aeroshell is DC-X's one-piece outer skin, made out of graphite fiber cloth impregnated with epoxy, extending from just below the nosecone to just above the maneuvering flap wells.)
DC-X was at 1200 feet when Conrad initiated the autoland, and reached a peak altitude of 2600 feet before beginning its descent. She landed on bare desert ground a hundred yards or so beyond the paved landing area. Other than producing a larger dust cloud than usual, the landing was without incident.
There was considerable confusion at first about exactly when the explosion took place, and about whether it was inside or outside the aeroshell. Much of this confusion got into the early reports. What follows isn't definitive, but it's pretty close.
What follows is from review of our video tape of the launch and of the vehicle back on its launch stand the next day. During the launch, someone in the FOCC (Pete Conrad?) was being piped over the PA; the FOCC announcements are audible on the tape. (We will be making this footage and other new material available as part of a mark 2 DC-X tape in the near future -- we'll announce it when it's ready.)
At about T-50 seconds, the engine precool started up, feeding liquid hydrogen through the engines to bring them down to operating temperature, producing the usual large vapor cloud around the base of the vehicle. Our vantage point was three miles west of the vehicle, looking down a shallow slope and out over the flat valley floor to the test site.
The breeze from our point of view was blowing left to right (out of the north) blowing the engine pre-cool vapor in a ground-hugging plume stretching 60-80 feet off to the right (south) of the ship, where the plume lifted off the ground, dispersing in another 50 feet or so.
Around T-3 seconds, one frame (1/30th of a second) after the first faint glow of engines igniting, there is an orange flash that hugs the ground under the pre-cool vapor plume, extending between the left side of the vehicle base and a point about sixty feet to the right of the vehicle base. There is a relatively dark section between the right side of the vehicle base and a point about twenty feet to the right of the vehicle base. Both ends of the bright section stretching between twenty and sixty feet right of the vehicle are sharply defined. This may in fact be two separate flashes, one under the vehicle from the engines and one off to the right of the vehicle.
The groundhugging flash only lasts one frame. The next frame shows what may be the start of another flash immediately to the right of the vehicle and extending perhaps a third of the way up the vehicle. The next frame shows this brightening and expanding, still sharp edged. Subsequent frames seem to show this subsiding to what appears to be the normal hydrogen vapor burnoff glow, less sharp edged and bright than the first three frames after engine ignition, extending perhaps halfway up the vehicle, but offset to its right from our point of view by the breeze.
Coinciding with the initial flash(es) a series of several sharp pops comes over the PA, lasting about a quarter second. The pattern of pops might or might not be similar to the brief series of concussive bangs we heard direct from the pad about fifteen seconds later. We couldn't resolve the PA pops on the tape with any certainty on our oscilloscope, an ancient bare-bones model. We speculate that the pops were concussion(s) picked up on the pad by one or more pieces of control or monitoring gear then transmitted electronically to the FOCC trailer, where the PA picked them up. The PA pops were all the same volume. The PA pop repeats and timing were likely indicative of how far from the launch stand the pieces of gear picking them up were.
The audible concussion(s) arrived, as we mentioned, about fifteen seconds after the initial flash. The tape shows two very loud and very sharply defined spikes about 55 milliseconds apart, the first spike slightly higher amplitude than the second, followed about a tenth of a second later by a lower-amplitude but relatively prolonged boom. (Fifteen seconds is approximately three miles worth of speed-of-sound delay.) To the ear, the delayed boom sounds like a diffuse echo of the initial bang(s) off the surrounding landscape.
We understand that the TV camera directly south (downwind) of the launch stand went dead one frame after the initial engine glow appeared.
We think it likely that the thick ground-hugging portion of the pre-cool hydrogen plume drifting downwind from the engines was concentrated enough to explode rather than simply burn off as we've seen on previous engine startups. It's possible that part of the plume may have been confined by some part of the ground service equipment. The plume concentration and ground-hugging path were both likely a result of the slow steady north wind plus the low temperature and thus high density of the air/hydrogen mix coming from under the vehicle.
There was definitely one and very likely two explosions in the launch stand area immediately after engine ignition. The second audio spike on the tape is unlikely to have been an echo of the first -- the perceived direction of the sharp double crack we heard was entirely from the pad area, and there was nothing suitable to act as a reflector of the sound either in the pad area or in the viewing area.
Our initial assumption was that engine ignition touched off the first explosion, but this doesn't account for the second concussion on the tape, or for the (ambiguous) video frame evidence that the initial ground hugging flash may have been separate from the under-vehicle engine glow.
Our best guess at this point is that hydrogen drifting downwind along the ground was ignited approximately sixty feet from the vehicle, resulting in the initial explosion, and that the blast from the initial explosion reached the downwind side of the vehicle 55 milliseconds later, touching off a second hydrogen explosion. The interval between the two audio spikes on the tape is consistent with a sonic-speed blast travelling approximately sixty feet. What this fails to explain, of course, is the near simultaneity of engine ignition and the explosion(s). We simply don't know what might have caused that.
We'd guess from the video and from the lack of damage to vehicle systems that this second explosion was also primarily outside the aeroshell, but we can't be 100% sure of this. Our close-up view of the DC-X on the pad the next day shows that while one edge of the split in the aeroshell is bent outward, overall the damage to the aeroshell seems to be an inward crumpling on the south side, from the top of the maneuvering flap to just under the nosecone. The outwardly bent edge might indicate an internal explosion, or it might be due to some combination of post-explosion "rebound" and aerodynamic forces. The portions of the tank and other internal equipment visible through the gaps in the aeroshell show no signs of scorching.
Inspection of our closeup video of the launch stand area the next day doesn't tell us much more - DC-X had been moved back to its launch stand, and the loose pieces of aeroshell had been collected and laid out next to the vehicle. The propellant loading pipes running south from the launch stand seem slightly scorched as compared to the pipes running north, but there is no obvious damage to them. Two items of equipment situated to the south of the vehicle at about the distance we think the explosion started were covered with tarps, but various other items in other locations were covered with tarps also; we can't draw any conclusions from that.
We also walked out past the official landing pad and saw the patch of desert where DC-X came down after this mission. The ground for a wide area around the test site is flat, bare of vegetation, apparently dried out mud, very hard-packed and fine grained. The low desert scrub vegetation doesn't start until well beyond the test area, where the ground starts rising toward the valley sides. DC-X's bare-ground touchdown site was marked by a wooden stake dead-center, probably because it wouldn't otherwise be visible far enough away to accurately determine range from the launch pad.
The actual landing marks were four shallow, roughly spherical-section pits dug out by the blast from the four engines, less than a foot deep and less than three feet wide each. We'd estimate nine inches deep at center and about thirty inches wide, give or take a bit. There was no sign of scorching -- the dirt apparently was just blasted away as dust. The landing did raise a large dust cloud that drifted away on the breeze afterwards.
The landing legs made no dents in the ground, but did leave visible scuff marks, apparently dark oxide rubbed off the bottom of the metal feet.
From what we saw of the aeroshell, it's going to need replacing. The contractor on that was Burt Rutan's Scaled Composites. He recently moved the company from California to Colorado, but we understand they do still have the production jigs for the DC-X aeroshell. Mr. Rutan was reportedly down in New Mexico at the end of last week to have a look at the damage, and presumably to give time/money estimates on repairing or replacing the aeroshell.
Preliminary word was nothing wrong with DC-X's machinery, but we would expect there will be much more thorough inspections before the bird flies again, in case anything got bent a bit by the concussion.
There was no major damage to the pad area that we could see, though we do know at least one camera died, and we'd be amazed if some of the gear near the explosion doesn't need repairs.
The original schedule called for three more flights before money ran out in late July. Presumably grounding DC-X will save some money for now, but repairs are likely to eat that and more. If DC-X can't be repaired in the next couple of weeks, chances are they'll need another million or two from either ARPA (who still have $35 million in unspent SSTO money) or NASA.
Space Access Society has survived two years of official existance as of Monday, July 4th. Membership is over 200 and growing ($30 US for one year's online membership, checks only please, remember to include an email address) and our influence extends well beyond our membership, due at least in part to the fact that we continue to spread this rag around on the nets for free.
The official story of SAS's start is that after years of planning we were established on July 4th, 1992 in a burst of patriotic fervor. Rumors that our illustrious founder was in fact trying to impress a girl he'd just met are of course totally false.
Seriously, it's been an interesting two years. Thanks, everybody. Fingers crossed, three more years just might see cheap access to space on the right track with unstoppable momentum.
And now, we're going to have to get hasty in finishing this, as we're late, we're late, we're very very late, and there's a lot of political news to cover. Forgive any rough edges from here on.
There have been rumors flying around for months, but now that Aviation Week has printed it, it's official: NASA is getting into the SSTO business. (Check out AW&ST, 6/27/94, pp. 22-23.) Of course, they're not calling it SSTO; the official NASA term apparently will be "RLV", for Reusable Launch Vehicle.
NASA is getting their toes wet in the field by setting up 16 nonprofit "cooperative agreements" with various companies to develop specific pieces of SSTO-related technology, with an emphasis on building and testing actual hardware. The cost over the next four years is expected to be $170 million, with NASA paying about 75% and the contractors paying the rest.The projects will be run by a new NASA Office Of Space Access and Technology (nice ring that "Space Access" has...), also called "Code X", presumably for the X-development hardware emphasis. Code X is to be formed from the Office of Space Systems and Development plus the Office of Advanced Concepts and technology. (Anyone who has info on the history and outlook of these outfits please drop us a note or give us a call.)
It's not clear yet who is to run Code X, though SAS thinks Colonel Simon Worden, former head of advanced technology projects (including DC-X) at BMDO, would be a good man to keep things under control and in focus over the next few years. He has a reputation for not being easily distracted, a useful trait for any would-be NASA cat-herder.
The DC-X-A project to rebuild DC-X over the next two years and use it as a "flying test stand" will come under the new outfit. NASA's future takeover of DC-X is still going forward, by the way, despite uncertainty over the remainder of this summer's flight test program.
On the whole, the new Office of Space Access and Technology seems to be a good thing; their initial project list includes a number of useful demonstrations of lightweight reusable structures, cryo tanks, and thermal protection. SAS's main cavil is that the engine development projects show a bit of an obsession with really large high-pressure tripropellant motors.
We'd like to see at least one effort to demonstrate a more conservative RLV-suitable bipropellant engine -- something along the lines of an RL-10 combining features already existing in various RL-10 versions: a 35Klb thrust upgrade, an extendable skirt (or other form of altitude compensation), and deep throttling capability, all in one engine which would then be extensively tested with an eye toward high reliability and incremental weight reduction.
Congress is off this week; Senators and Representatives will generally be easier to reach via their local offices than in DC. Congress will be back in session Monday, July 11th.
Meanwhile, here's a quick overall status report on SX-2 funding.
The House FY'95 DOD Authorizations bill has passed, with $100 million for SX-2 along with very favorable report language.
The Senate FY'95 DOD Authorization was almost finished at the end of last week. It zeroes SX-2 funding -- but as you'll recall, SX-2 funding lost a close 10-11 vote in the Senate Armed Services Committee.
The SASC membership will very likely be the Senate delegates to the House- Senate DOD Authorizations conference. If we can keep our friends on the HASC and SASC, and turn around one or two of our opponents on SASC, we should get SX-2 funding in the final DOD Authorization bill. This conference will get underway shortly after Congress is back in session next week.
The House FY'95 DOD Appropriations bill has also passed. The good news is that it contains $50 million for SX-2, which along with the $35 million in FY'94 SSTO money still languishing in ARPA should be enough to get SX-2 off to a good start.
The bad news is that the accompanying report language has two SX-2 killer clauses. One directs that the money be used to develop reusable technology components for expendables (!) and the second says that the money goes away entirely should the White House as expected direct that NASA take the lead on developing SSTO technology.
We hear that a HAC Defense subcommittee staffer took it upon himself to insert these clauses. We hear that it's the same guy who pulled a similar stunt last year. We understand that these gotcha clauses will be taken care of, one way or another, but we can't help wondering how long the subcommittee chairman will continue to put up with this sort of nonsense.
On the Senate side, the DOD Appropriation will match the Senate's DOD Authorization: Zero funds for SX-2. We understand however that if we can get SX-2 funding through the Authorizations conference, the Appropriations conference will also very likely end up following the House version and fund SX-2 at an adequate level. The House-Senate DOD Appropriations conference isn't due until early August.
We have something new here, actual NASA funding for SSTO-useful technology development projects -- and it could be in trouble only a week after the projects were officially announced. Some things never change.
We don't yet have a comprehensive picture of the NASA RLV funding status. We do know that the House has authorized $40 million for NASA SSTO work in FY'95, and that NASA is moving ahead on the DC-X-A plan (among other projects) on that basis.
We understand there's a potential problem on the Senate side. Apparently someone in Senator Barbara Mikulski's office opposes giving NASA any SSTO funding. Senator Mikulski (D, MD) chairs the Senate Appropriations Committee's HUD VA and Independent Agencies subcommittee, which oversees NASA appropriations, so this could be a problem if the case for moving ahead with SSTO development isn't brought to her attention.
The top priority right now is to get SX-2 funding out of the House-Senate Defense Authorization conference, which should be underway early next week. To do that, we need to reinforce our existing support in both House and Senate, and also pick up some new support on the Senate side.
Write a brief thank-you note to any of these Senators from your state who supported SX-2 in the SASC vote.
Call, fax, or write any of these Senators from your state marked as having voted against SX-2 funding, and ask them to support SX-2 in the conference.
For the rest of this week, call or fax them in their home-state office -- you can get the voice number from your phone book "Blue Pages", the US government section, under "Senators". From Monday on, use the DC numbers.
If you phone, tell whoever answers that you're calling about the Defense Authorization conference. They may pass you on to someone else at that point, or they may take the call themselves. Ask them to accede to the House position and fund the SSRT (Single Stage Rocket Technology) "SX-2" project. If they want to know more, fill them in as best you can; otherwise thank them for their time and ring off.
If you fax or mail a letter, state your basic point (you'd like them to accede to the House's $100 million funding level for the SSRT "SX-2" in the FY'95 DOD Authorization conference) at the start. Go on to tell them a bit about the project and why you think it's important, if you feel like writing more. Keep it under a page, though, and above all keep it polite.
Late news -- We hear that Senator Hutchison plans to support us, while Senator Graham of Florida is wavering on the theory that NASA will do everything that needs to be done with SSTO. In the latter case, we recommend that you emphasize how SX-2 complements NASA's plans, filling in the gap between now and 1997 when NASA would get a demonstrator project started. SX-2, of course, is planned to fly in '97.
-- Senate Armed Services Committee (SASC) --
("Senator XYZ", office#, "Washington DC 20510" will get mail to them.)
(Senators marked with a "*" either voted against SX-2 funding or were absent)
Name office# phone fax (AC 202)
* Sam Nunn (D-GA) SASC Chair SD-303 224-3521 224-0072
Strom Thurmond (R-SC) RRM SR-217 224-5972 224-1300
* James Exon (D-NE) SH-528 224-4224 224-5213
John McCain (R-AZ) SR-111 224-2235 224-8938
* Richard C. Shelby (D-AL) SH-509 224-5744 224-3416
William S. Cohen (R-ME) SH-322 224-2523 224-2693
* Edward M. Kennedy (D-MA) SR-315 224-4543 224-2417
* Carl Levin (D-MI) SR-459 224-6221 224-1388
* Dan Coats (R-IN) SR-404 224-5623 224-1966
Trent Lott (R-MS) SR-487 224-6253 224-2262
Bob Smith (R-NH) SD-332 224-2841 224-1353
Jeff Bingaman (D-NM) SH-110 224-5521 224-2852
* John Glenn (D-OH) SH-503 224-3353 224-7983
John Warner (R-VA) SR-225 224-2023 224-6295
* Joseph I. Lieberman (D-CT) SH-316 224-4041 224-9750
Bob Graham (D-FL) SH-524 224-3041 224-6843
Dirk Kempthorne (D-ID) SD-367 224-6142 224-5893
Lauch Faircloth (R-NC) SH-702 224-3154 224-7406
* Charles S. Robb (D-VA) SR-493 224-4024 224-8689
* Robert C. Byrd (D-WV) SH-311 224-3954 224-8070
* Kay Bailey Hutchison (R-TX) SH-703 224-5922 224-0776
* Richard H. Bryan (D NV) SR-364 224-6244 224-1867
There are a couple of key people in the House Armed Services Committee whose help we could use. If you live in their districts, call, fax, or write in support of SX-2 funding in the conference.
Representative Ron Dellums (D CA) HASC Chairman 2136 RHOB, Washington DC 20515 (202) 225-2661 voice, 225-9817 fax Representative Floyd Spence (R SC) HASC RRM (Ranking Republican Member) 2405 RHOB, Washington DC 20515 (202) 225-2452 voice, 225-2455 fax Representative Bob Stump (R AZ) HASC R&T Subcommittee RRM 211 CHOB, Washington DC 20515 (202) 225-4576 voice, 225-6328 fax
There are also some people on the House side who've been very helpful and could use some thanks. If you live in their districts, drop them a note of appreciation for their support for SX-2.
Representative John Murtha (D PA) 2423 RHOB, Washington DC 20515 Representative Norm Mineta (D CA) 2221 RHOB, Washington DC 20515 Representative Anna Eshoo (D CA) 1505 LHOB, Washington DC 20515
While SAS is wary of NASA's future handling of SSTO, we feel that early indications are that NASA's announced "RLV" technology demonstration projects may in the near term produce hardware and techniques useful to SSTO developers in general. We recommend that people from Senator Mikulski's state (Maryland) phone, fax, or write her office in support of $40 million in FY'95 NASA SSTO/RLV funding.
Senator Barbara Mikulski (D MD) SAC HUD, VA, & Independent Agencies Chair SH709, Washington DC 20510 (202) 224-4654 voice, 224-8858 Henry Vanderbilt "Reach low orbit and you're halfway to anywhere Space Access Society in the Solar System." 4855 E Warner Rd #24-150 - Robert A. Heinlein Phoenix, AZ 85044 602 431-9283 voice/fax "You can't get there from here." (hvanderbilt@bix.com) - Anonymous -- Permission granted to redistribute the full and unaltered text of this -- -- piece, including the copyright and this notice. All other rights -- -- reserved. In other words, intact crossposting is strongly encouraged. --