Letter from Chris Stratford of Tokyo, observing that in projects such as Lockheed's Aeroballistic Rocket, development costs dominate construction costs, which in turn dominate fuel costs. "Quantum reductions in cost come from streamlined engineering and lower airframe expenses; consumables are not the main cost driver..." Given this, hypersonic air-breathing propulsion [advocated by the NASP groupies, but not used in Lockheed's concept] is probably not a good way to reduce costs.
Letter from Chet Richards, observing that given SSTO transport to orbit, the remaining crucial step to reducing payload costs is in-orbit assembly in a shirtsleeves environment -- a pressurized assembly facility. This would eliminate the need to design fully-assembled spacecraft to survive launch loads, and would permit easy in-space testing of prototypes. "The station we really need is a small city, not a four-man outpost. This is within our existing technical and financial capabilities. We simply need to learn a new way of conducting business."
NASA is supplying startup funding for hypersonic-aeronautics courses at three universities, observing that hypersonics research is dominated by people trained in the 1950s and 1960s, many of them due to retire soon.
USBI trying to validate techniques for testing the strength of used shuttle-SRB drogue parachutes, in hopes of extending their operational life. If the techniques work out, USBI plans to test the current "fleet leader" -- a drogue chute which has reached the current ten-flight limit -- to destruction to confirm that it is still strong.
Panamsat adds a fourth Hughes HS601 to its current Hughes contract; the bird is meant as a ground spare.
Pentagon investigation confirms the existence of an early-1980s campaign to supply disinformation to the Soviets about US ABM work, but finds that it was terminated ten months before the successful Homing Overlay Experiment test. The early (unsuccessful) HOE tests carried a system designed to make a near-miss look like a direct hit, but none of those tests came close enough to activate it. The Administration decided that compromising potentially-successful tests with extra complexity was not worth the gain from fooling the Soviets. The investigation also concluded that allegations that the successful test was rigged are false.
Senate appropriates $14.6G for NASA, paring various programs somewhat and telling NASA that $160M of its ASRM request must come out of other programs. Another political battle over the station is imminent; the Senate is felt to be a bit friendlier than it was, but the question of Russian participation remains a major unknown.
NASA submits new station baseline design, temporarily dubbed "Alpha", to the White House... without cost numbers, which are running late. Alpha is probably a rather academic exercise, since it's now clear that what the White House really wants is to bring the Russians on board, and the plan for that is still in the works. Alpha does have a few interesting features. It reinstates the alpha joints for the solar arrays, allowing Sun tracking with minimal disturbance to microgravity work. It also restores the full US lab module and the connecting nodes. Most important, though, it is set up so that the arrangement of the NASA/ESA/NASDA/CSA components remains much the same even if more Russian hardware is added. It provides three options, in fact: build along current lines using Lockheed's Bus-1 for propulsion and control, do likewise but using the Salyut FGB space tug instead of Bus-1 (the tug's capabilities are described as "extensive and impressive"), or combine with Mir 2 and a joint US-Russian solar- dynamic power system.
O'Connor says that the Salyut FGB would be cheaper than Bus-1, can be refuelled in orbit, and (unlike Bus-1) already has enough attitude-control authority for the station's needs. According to KB Salyut, the tug has flown on four Cosmos missions, delivered Kvant 2 to Mir, and is planned for Priroda and Spektr.
All the Alpha options assume availability of either ASRM or the lightweight aluminum-lithium external tank, to increase shuttle payload. Construction would begin in late 1998 and be complete in 2003 after 19 shuttle flights. Mixed in with those would be 7 more flights, starting spring 1999, using the facility in man-tended mode.
The third-option unified station would be in a 51.6deg orbit, and would use a rather different assembly sequence, with most of the early flights Russian. Assembly could start in 1997, it would need at least four fewer shuttle flights, and it would have a crew of six rather than four. NASA is concerned about issues like how the station would be developed and operated and how much responsibility would be delegated to contractors.
Congress is dissatisfied with the fuzzy nature of all this, and wants to see specifics on exactly what Clinton and NASA want to build. The international partners likewise are reserving judgement pending further information, although they cautiously approve of some of the Alpha changes. They want to see a backup plan in case Russia is unable to meet its new commitments, and are concerned about extra costs resulting from the schedule slips revealed in Alpha (although ESA, in particular, may be as much relieved as concerned, because its budget crunch was endangering the schedule for the Columbus module anyway). The partners want to see Russia participating on equal terms, not a "US buyout" of the Russian space program. There is also concern about whether the existing partners will be relegated to a second-class role in a US-Russian station, and about whether RKA has adequate control over NPO Energia to keep things on schedule in Russia.
STS-63, set for launch in mid-1994, will carry Vladimir Titov -- now in training as backup cosmonaut for STS-60 (set for January) -- and also the program's first female pilot, Eileen Collins as copilot.
Succesful Atlas launch of a USN UHF-Follow-On comsat, replacing the one that was left in a useless orbit by the last Atlas failure. Hughes is relieved, since its Navy contract specifies delivery on orbit, and the loss of one bird was painful enough. The Navy is happy, because the new birds will replace a "motley constellation" of aging military comsats and leased commercial-comsat capacity that is overloaded enough to be turning away potential users. And General Dynamics is seriously happy that Atlas is now behaving itself again.
Discovery launch, carrying ACTS, postponed two days to accommodate review of components that ACTS might have in common with Mars Observer. It was built by the same group, now Martin Marietta Astro Space. Engineers have completed reliability tests on two transistors in TOS that come from the same batch as the suspect ones on MO, and cleared them for flight.
NASA has also raised the minimum fuel reserve required for shuttle reentry, after Endeavour's fuel consumption during its reentry from the Eureca retrieval was substantially higher than normal. It's thought that the orbiter encountered a large number of rapid changes in atmospheric density at high altitude. There is particular concern because Endeavour could easily have been somewhat low on fuel by that point: the Eureca retrieval went very smoothly and fuel consumption for it was minimal, but other rendezvous missions in the past haven't been so economical. The increased reserve will require more cautious planning of rendezvous missions in future.
White House releases its much-promised "Reinventing Government" study, proposing reduction of redundancy and elimination of waste. [Yeah, sure.] Space-related items include combining the civilian and military polar-orbit weather-satellite systems and consolidating three existing administrative groups -- one of them the moribund National Space Council -- into a National Science and Technology Council. Some of the other items are likely to provoke Congressional opposition, however, and just what will happen is unclear.
USN hypersonic-windtunnel tests confirm that small design changes, including blunter leading edges, can make "waverider" high-hypersonic aircraft much less sensitive to exact flight conditions than classical waverider designs, at relatively modest performance cost. The tests found that the model had L/D of 3.8, against 4.5 for a traditional sharp-edged waverider, and that this varied less than 10% over a wide range of conditions.
Russia has tested a TV-aided remote-control docking system for use with the Progress freighters. Early this year, Gennadi Manakov, aboard Mir, undocked a Progress, maneuvered it nearby, and redocked it, using the system prototype. Progress normally docks using the automatic Kurs system, but the TV system will be a useful backup and will probably be preferred if Mir is temporarily unmanned for some reason. Normally, the operator will be on the ground rather than on Mir.
Russians plan an EVA to inspect Mir for signs of Perseid damage. Tests will be done first to determine whether the solar arrays have experienced significant output losses from Perseid impacts, although it's thought that any reduction is minor. Contrary to some previous reports, the EVA will not use the maneuvering backpack -- it has been idle for some time and the Russians would want to give it a major checkout first.
The Progress M-17 freighter, now separated from Mir, will remain in orbit for 12-18 months rather than being commanded into a destructive reentry immediately. "American specialists asked us how long can Soyuz fly in space, and since Progress is similar in its design and major systems, the test with M-17 will provide good data."
NASA plans an effort to improve assessment of spacecraft risks due to meteor showers like the Perseids. When it was noticed that Discovery's 4 Aug launch date would have it up during the Perseids, JSC tried to compute the probability of trouble... and discovered that the uncertainties in the calculations were huge, because meteor-shower behavior is not well understood. So Discovery's launch was postponed, and Hubble and EUVE were reoriented to minimize their exposure. The Perseids were a bit of a dud this year, but there is still a good chance of a major Perseid storm in the next year or two, and a strong possibility that the Leonids will storm late this decade, so NASA is seeking data from new instruments in hopes that better risk estimates can be made.
Weather-satellite image from NOAA-11, showing the Midwest floods via a large Sun glint from flooded land between the Mississippi and Missouri.
UK Civil Aviation Authority to provide startup funding for an Institute of Satellite Navigation at Leeds.
France is sounding out Russia about the possibility of a joint European antimissile system, possibly based on the Russian SA-12 antiaircraft missile. An SA-12 battery successfully killed 8 "Scud-type" missiles with nine SA-12s in tests earlier this year. The Russian officer in charge says his unit already has the capabilities that Patriot will acquire with the PAC-2 updates in 1995. The SA-12 has been seriously secret until fairly recently.
Editorial urging the US government to get its act together on future launcher-development policy, preferably via a serious attempt to build an all-new launcher in the next decade. The editorial also suggests that it might be a good idea to keep the STME team together, as one of the few efforts the US has made recently to improve propulsion technology.
Study it forever and you'll still | Henry Spencer @ U of Toronto Zoology wonder. Fly it once and you'll know. | henry@zoo.toronto.edu utzoo!henry