DC-X is a low-speed flight regime testbed for a proposed reusable rocket- powered Single Stage To Orbit (SSTO) transport, McDonnell-Douglas Aerospace's "Delta Clipper". DC-X is intended to prove out rocket-powered vertical takeoff, nose-first lifting-body to tail-first flight transition, and tail- first landing. It is also intended to prove out rapid turnaround of a reusable rocket by a minimal ground support crew. DC-X is being tested and flown by approximately thirty people.
DC-X has already pretty much proved out rapid low-cost development of an advanced aerospace X-vehicle type engineering testbed by a small highly- motivated engineering team on a tight budget. DC-X was built by less than two hundred people, in less than two years, for about $60 million. Of course, this sort of thing has been done before -- just not recently.
DC-X stands 40 feet tall, is 13 feet across the base, and is roughly cone- shaped, with a circular cross-section forward blending into a square base. The vehicle has four maneuvering flaps, one set into each side near the base, and sits on four landing legs. DC-X masses 22,300 lbs empty and 41,630 lbs fully fuelled, and is powered by four 13,500 lb thrust Pratt & Whitney RL-10- A5 liquid oxygen/liquid hydrogen rocket motors, each able to gimbal +- 8 degrees. The RL-10-A5 is a special version of the RL-10-A designed for wide throttling range (30% to 100%) and sea-level operation.
The single DC-X vehicle was officially rolled out of its construction hangar at MDA's Huntington Beach CA plant at the start of April, then trucked out to White Sands, New Mexico for ground and then flight tests.
Between Thursday, May 20th and Thursday, June 17th, DC-X underwent a series of nine engine firings/vehicle systems exercises, including two firings in one day with complete defueling/vehicle servicing/refueling in between.
On Friday, June 18th, the DC-X crew began breaking down the ground support equipment and moving it to the White Sands Missile Range (WSMR) flight test site, a distance of about fifty miles. Meanwhile DC-X was stored in a hangar.
On Friday, July 16th, the ground support equipment move was completed. DC-X was taken out of storage, trucked out to the flight test site, and hoisted upright onto its launch pad.
On Monday, July 19th, the DC-X crew began running a series of ground tests to make sure everything had made it over intact and was hooked back together properly.
DC-X is currently at the White Sands Missile Range (WSMR) flight test site, undergoing final ground checkout before flight test gets underway.
The pre-flight checkout looks like culminating in a "burp test" this weekend. This will be a four-second "hot firing" of DC-X's engines, with DC-X locked down on the launch pad, to check that all the plumbing is OK. The plan is to do this tomorrow, Saturday. If things run late they'll come back and do it Sunday. Up till now they've generally been taking Sundays off.
If this hot firing test doesn't find any problems, the "bunny hop" flight stability test series should start one week later. The first of these stability test flights is tentatively set for -- wait for it -- Friday the 13th, with Saturday and Sunday of that weekend as the backup dates.
These flights will consist of takeoff, sideways transition of several hundred feet, and landing, done under varying wind conditions. A lot of people will be keeping their fingers crossed during the initial "bunny hop", as it will be the first real-world test of DC-X's stability at low speed and altitude, a critical and hard-to-simulate part of the VTOL (Vertical Takeoff and Landing) flight envelope.
The official "first" DC-X flight will actually be the initial flight of the second test series, when they'll be going for higher speeds and altitude. This will be the one with speeches, hoopla, VIP's, and media coverage, but alas still no admission of the general public. Chances are good for TV coverage though, between NASA Select, local TV stations, and the national networks. Chances are too that you'll have a better view on TV, since the "VIP" viewing site will be five miles from the pad.
At this point the "first" flight looks like taking place two weekends from now. McDonnell Douglas says "no later than Monday August 23rd", assuming all goes well in the meantime. Given that the invitations mention a tour of the test site the day before, with the actual flight at 8 am local time (10 am Eastern), Sunday the 22nd seems most likely, with the 23rd as backup date. This assumes that they want to let the invitees fit the trip into a weekend. This may not be the DC-X crew's highest priority, however, and rightly so.
The end-for-end transition maneuver won't be tried until the third, final flight test series.
The current DC-X program is funded through flight test and data analysis this fall, and ends after that. There is an ongoing effort to get the US Congress to fund a three-year followon program, currently called SX-2 (Space Experimental 2). This tentatively looks like being a reusable suborbital vehicle powered by 8 RL-10-A5 engines, capable of reaching Mach 6 (about 1/4 orbital velocity) and 100 miles altitude, built with orbital-weight tanks and structure, and able to test orbital grade heat-shielding.
The SX-2 program goal will be to demonstrate all remaining technology needed to build a reusable single-stage-to-orbit vehicle. Once SX-2 has been tested, all that should be necessary to produce a functioning reusable SSTO is to scale up the SX-2 structures and install new larger rocket engines.
Proposed FY '94 funding for SX-2 startup is $75 million. Total SX-2 program cost over the next three years would be very much dependent on the contractor chosen and the details of the design, but would be on the order of several hundred million. This is the same order of magnitude as typical recent X- aircraft programs such as the X-29 and X-31.
The $75 million SX-2 startup money now looks like being added to the Advanced Research Project Agency (ARPA) budget, with at least some of the funding in following years to come from other interested arms of the government. SX-2 would still be run by the current BMDO (formerly SDIO) DC-X management team, even though funded via ARPA, at least under the current House version of the FY '94 Defense Authorization Bill.
The House of Representatives now seems favorably disposed toward SX-2. The biggest hurdle ahead this year will probably be convincing the Senate to go along when the House-Senate conference committee meets to work out the differences between the two versions of next year's Defense budget.
** This is the section of the House Defense Authorization Bill approved last ** week that covers DC-X (SSRT) Followon.
(a) Program Funding -- the Secretary of Defense shall establish a Single Stage Rocket Technology program and shall provide funds for that program within funds available for the Advanced Research Projects Agency. That program shall be managed within the Office of the Undersecretary of Defense for Acquisition.
(b) Funding -- Of the amount appropriated pursuant to section 201 for Defense-wide activities, $79,880,000 shall be available for, and may be obligated only for, Single Stage Rocket Technology.
** This is the section of the report accompanying the House Defense ** Authorization Bill that covers DC-X Followon. The report language is ** intended to clarify the intent of the bill. From The House of Representatives Committee on Armed Services Report on the FY '94 Defense Department Authorization Bill, H.R. 2401 H. Rpt. 103-200, 103rd Congress, 3rd Session; July 30th, 1993, pp. 172-173
The budget request included $4.88 million for single stage rocket technology (SSRT), also known as single-stage-to-orbit (SSTO), within the Ballistic Missile Defense Office (BMDO) follow-on technologies program to complete the final testing in phase one of the program.
The United States spends over $30 billion each year on space programs. Yet, unlike many other commercial activities that have benefitted and achieved greater efficiencies from military research and development, U.S. commercial launch costs are at least twice -- and in some instances as much as ten times -- the costs of foreign competitors. Similarly, it takes the United States at least four times as long to provide launch services to any given user.
The Congress must remain skeptical and avoid fully embracing the sometimes overly optimistic claims regarding SSRT/SSTO technology. Yet, if the United States is to regain its international competitiveness in this critically important military and economic area, it must pursue promising enabling space launch technologies that have the potential of dramatic reductions in launch costs.
Accordingly, the committee recommends the following:
None of the additional funds recommended to be authorized may be obligated until the congressional defense committees have been provided with a phase two program plan outlining objectives and technical milestones and certifying that funding support has been established for fiscal years 1995 and 1996.
** End of report excerpt
On the whole, this looks good. The open competition clause is no great surprise -- McDonnell-Douglas obviously would have liked a no-bid contract that would guarantee them another major step toward an operational Delta Clipper, but a no-bid on a program of this size would be extraordinary. As it is, MDA will probably have the inside track on SX-2 _if_ DC-X flight test goes well. Chances are though that Lockheed, and possibly Boeing and Rockwell too, will also bid. General Dynamics, alas, seems too busy dismantling itself to take an interest.
One possible problem with this report language is in the last paragraph, the phrase about "certifying funding support for fiscal years 1995 and 1996". Our best guess as to what this means is that ARPA will have to find major funding sponsors in other government agencies and/or private industry for the hundred million-plus '95 and '96 SX-2 budgets, before ARPA can go ahead with any major SX-2 startup spending. Multi-agency/multi-company funding is likely to complicate SX-2 politically, with some danger of it bogging down the way NASP has. We will need to watch for signs of this over the next few years, assuming we do get SX-2 startup funded.
Meanwhile, Congress has left on its August recess. They won't be back in session until the second week of September, barring national emergencies. Both the House and Senate left town with Defense Authorization bills out of committee but not yet approved "on the floor" (by the entire membership). The House version contains the above language, the Senate version contains much less favorable language mentioning SSTO along with NASP and Spacelifter in a single $30 million USAF line item.
Neither the House nor the Senate is likely to amend the SSRT sections of their Defense Authorization bills during floor debate. We could wish for favorable amendment on the Senate floor, and it's worth asking for, but it doesn't seem likely to happen.
Once the full House and Senate approve their Defense Authorizations, the next milestone is the House-Senate Conference Committee, when the two bodies will resolve differences in the two versions of next year's DOD budget. This will be critical to us; we need to get the House version SSRT wording adopted. The House-Senate Defense Authorization conference should be in mid-September.
After that, the Appropriations process starts, in which the Congress "writes the check", so to speak, for the projects approved in the Authorizations bill. More on this next week.
If you have any contacts in the Senate Armed Services Committee, go on working them low-key -- there's no telling who will be on the Conference Committee, and we'll need all the help we can get on the Senate side when that eventually gets underway.
Other than that, stay tuned for updates, and enjoy the summer.
Senate Armed Services Committee Members List
Name office# phone fax (AC 202)
("Senator XYZ", office#, "Washington DC 20510" will get mail to them)
Sam Nunn (D-GA, chairman) SD-303 224-3521 224-0072
Bob Smith (R-NH, RRM) SD-332 224-2841 224-1353
James Exon (D-NE) SH-330 224-4224 224-5213
John McCain (R-AZ) SR-111 224-2235 224-8938
Richard C. Shelby (D-AL) SH-313 224-5744 224-3416
Joseph I. Lieberman (D-CT) SH-502 224-4041 224-9750
Bob Graham (D-FL) SD-241 224-3041 224-6843
Dirk Kempthorne (D-ID) SDB40-3 224-6142 224-5893
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-504 224-5623 224-1966
Trent Lott (R-MS) SR-487 224-6253 224-2262
Lauch Faircloth (R-NC) SH-716 224-3154 224-7406
Jeff Bingaman (D-NM) SH-524 224-5521 224-1810
John Glenn (D-OH) SH-503 224-3353 224-7983
Strom Thurmond (R-SC) SR-217 224-5972 224-1300
John Warner (R-VA) SR-225 224-2023 224-6295
Charles S. Robb (D-VA) SR-493 224-4024 224-8689
Robert C. Byrd (D-WV) SH-311 224-3954 224-8070
Henry Vanderbilt "Reach low orbit and you're halfway to anywhere
Executive Director, in the Solar System."
Space Access Society - Robert A. Heinlein
hvanderbilt@bix.com "You can't get there from here."
602 431-9283 voice/fax - Anonymous
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