DC-X Background (no change in this background section since 7/14 report)
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 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. Of course, that's 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.
This brings us up to the present. Final pre-flight testing is still underway, taking a bit longer than the DC-X crew had hoped. New Mexico is in the middle of "monsoon" season, with frequent thunderstorms and blowing dust to gum things up. Chances are the minor glitches normal to this sort of experimental program also contribute to the slow going. The test crew does seem to have a commendable determination not to give in to "schedulitis" and fly before they're ready. Things are running about a week to ten days behind the tentative target dates posted at the start of July.
The ground tests currently look like culminating in a "burp test" late next week. This will be a four-second "hot firing" of DC-X's engines on the launch pad to check that all the plumbing is OK.
If the hot firing doesn't find any problems, the "bunny hop" flight stability test series should start shortly afterwards, possibly during the week of August 9th. These hops 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 envelope. Fingers crossed, everybody.
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. At this point the "first" flight looks like taking place in mid-to-late August. 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.
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 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. The money would come out of the $3.8 billion BMDO budget already pretty much agreed on for the coming year. 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.
SX-2 would start out under BMDO (formerly SDIO), so support from members of the House and Senate Armed Services Committees (HASC and SASC) is vital. The actual name they know SX-2 by is "followon funding for BMDO's SSRT (Single Stage Rocket Technology) program." The specific action we're calling for is for Congress to authorize $75 million in existing BMDO funding for this project next year -- we are not asking for any new funding authority, but rather for reallocation of existing funding toward a DC-X followon.
Representative Schroeder's House Armed Services Committee Research and Technology Subcommittee (HASC R&T for short) marked up their version of the DOD FY '94 Authorization Bill on Monday the 26th. They included the $75m we've been asking for a DC-X followon program startup next year, as well as $5m for winding up the current DC-X program. We've won a major battle in the fight for affordable access to space, and everybody who's worked on this deserves congratulations. Three cheers for us!
The full HASC marked up yesterday, and we have no reason to believe there were any changes in DC-X followon funding. The actual text of the DOD bill they approved won't be out for a few more days though.
The $75m was, we are told, accompanied by language directing that DC-X Followon be transferred from BMDO to ARPA, the Advanced Research Projects Agency, but also directing that the current BMDO DC-X management team be kept on the project. One way of looking at this is that BMDO will run SX-2 as a contractor for ARPA -- this is a normal way of doing business for ARPA, which has a very small staff coordinating a lot of projects.
This may or may not be good news. ARPA in theory is a more appropriate place for developing an X-rocket, but the current arrangement at BMDO is one we KNOW works. Practically speaking though, BMDO is likely to be under heavy political pressure over the next couple of years. Chances are that they wouldn't have been allowed to continue developing a reusable X-rocket in- house anyway. The move to ARPA was probably inevitable. We'll just have to watch how the program goes over the next few years, and be ready to raise a fuss if it shows signs of the sort of bureaucratic bog-down BMDO has been so good at avoiding.
Meanwhile, we need to stay awake for the next couple of weeks. The next step is for the full House of Representatives to consider and vote on the DOD funding bill. This may or may not happen before the one-month Congressional recess starting August 9th. It's not likely, but there is always a chance our project could be cut when this goes to the full House. Moving from BMDO to ARPA is probably a plus here; BMDO is a likely target of further attempts to reduce defense spending on the House floor.
Once the full House approves the Defense bill, the next milestone is the House-Senate Conference Committee, when the two bodies will resolve differences in their versions of next year's DOD budget. You may recall that we got very little of what we need in the Senate version - a single $30m line item in the USAF budget for SSTO, NASP, and Spacelifter combined. We'll need to make a maximum effort to let both sides of the Conference Committee know what we want when the time comes. That almost certainly won't be until after the recess, however.
You might drop a note to Representative Dellums, Representative Schroeder and any other HASC members you have been in touch with, thanking them for their support. 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.
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 -- 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. --