Slashdot Mirror
NASA To Try To Resume Flights By Fall
underground alliance writes "According to BBC News, space shuttle flights could resume as early as this fall. The article says that 'Engineers have been put on standby to fix problems already raised by the investigating board, and devise a way of checking the exterior shuttle for defects while it is in orbit.' I think that this is a good move especially since ISS construction has been put on hold because without the space shuttle. The space shuttle is the only heavy freighter and the only means of putting a new ISS component in space."
Unless Shuttle is going to the ISS, they can't go there for an emergency without alot of things all working out.
This was covered here at the time of the accident.
It needs to carry the orbiter docking system. In a bind, however, transfers via EVA (space suits) mightbe possible. The station has 2 Russian suits and 2 US suits. Shuttles typically have 2 US suits.
Shuttle and ISS aren't on the same orbit unless Shuttle is expressly going there, and for a mission like Columbia's there wasn't enough fuel to make the orbit change.
Columbia launched to a 39 degree inclination. The Space station is at a 51.6 degree inclination.
Only the OMS and RCS engines are available in orbit, and their capability is roughly 1250 feet per second, or about 1400 km/h speed change (delta v).
Wouldn't it make sense to keep an extra Orbiter in space, docked to the ISS?
By doing that you essentially cut the usable shuttle fleet in half, with the lose of Columbia and the loss of use of another shuttle parked in orbit. Castrates the STS usability and turnaround time. Plus, you leave an orbiter with a lot longer exposure to micrometeroid strikes than nominal orbital excursions. Also a greater chance of it getting damaged by orbital junk, if you believe that may have been a contributing cause to Columbia's loss. And the long-term exposure to space is a question mark as it wasn't really desigined for that.
Lots of info from discussion in sci.space.shuttle is compiled in the Columbia Loss Faq. It's worth a read before asking questions...
-r
-'fester
That's a moot point. If you check NASA's launch schedule, you'll find that the missions for the forseeable future after Columbia's were dedicated to ISS:
- March 1: STS-114 Atlantis to the ISS.
- May 23: STS-115 Endeavour to the ISS.
- July 24: STS-116 Atlantis to the ISS.
- Oct. 2: STS-117 Endeavour to the ISS.
- Nov. 13: STS-118 Columbia to the ISS.
- [see the rest]
There was only one non-ISS flight still on the books, the final Hubble repair mission (STS-122).A shuttle at ISS doesn't need Canadarm, ISS has got Canadarm2 which is bigger and better. A shuttle at ISS doesn't need EVA packs, ISS has got both Russian and US EVA packs and two separate airlock systems. A shuttle at ISS doesn't need a rescue system, the astronauts can camp out there (albeit uncomfortably) for as long as it takes to bring them down with Soyuz or other shuttles (or OSP in the future).
Basically, NASA was extremely unfortunate by having this failure happen on the last flight it could have happened on.
Slashdot monitor for your Mozilla sidebar or Active Desktop.
They did, several years ago. But they had a small supply of old tanks (with the old foam) in their inventory. Columbia's flight used the second last of these old tanks.
In fairness, the issue of falling foam was known, but it wasn't considered to be a danger, just an annoying bug. Heck, even a month *after* the accident, the best minds on the planet still can't figure out how the foam drop could have done enough damage to threaten the orbiter.
Slashdot monitor for your Mozilla sidebar or Active Desktop.
>No, the space station was placed in that orbit as a compromise
>so that both the American (Shuttle) and the Russian (Soyuz)
>vehicles could get to it. Baikonur [astronautix.com] and Cape
>Canaveral [nasa.gov] are at quite different lattitudes. ISS is
>half way in between.
Yes, true to a point - and it was a stupid compromise. Had we relied on the cheaper, more reliable Russian boosters and scrapped utilizing the Shuttles for ISS construction, crew delivery and resupply, the ISS could have been placed into a substantially higher orbit, requiring fewer reboost missions and therefore becoming inherently cheaper to operate.
Compare the cost of launching unmanned payloads (say, ISS components) on a Russian Proton rocket to the cost of launching them on the Shuttle. It costs around $4,729 a pound to put a payload into low earth orbit with the Shuttle, as opposed to $1,953 a pound with the Proton. Proton can't launch payloads that are quite as large as the Shuttle's (19,760 kg for the Proton vs. 28,803 kg for the Shuttle), but the cost per pound for the Russian vehicle is vastly lower. As opposed to the $300 million plus launch cost of a Shuttle, a Proton costs a comparatively paltry $85 million to build and launch.
And you don't need a rocket as big as a Proton to launch men into space - the Russians routinely send people to the ISS aboard the relatively tiny Soyuz rocket, which only has a capacity of 7,000 kg and costs just $37 million to build and launch (the per-pound cost is also cheaper than the shuttle - $2,432). Compare this to the Shuttles, which cost at least $2 billion to build each (probably more, if you factor in R&D), and well in excess of $300 million each launch (some accounting puts Shuttle launches at an incredible $500 million each).
There also hasn't been a fatal accident involving Soyuz since the 1970's, when an air seal failed during reentry and the crew suffocated. There was a serious accident during the '80s when the booster failed, but the cosmonauts were able to successfully escape the destruction of the vehicle and came away with only minor injuries. That's simply not possible with the Shuttle, since the astronauts are strapped right next to huge tanks of liquid hydrogen and liquid oxygen (an insanely stupid design - there's no way to be safely blown clear).
There have been something like 1,600 launches of Soyuz-family rockets, as opposed to a little more than 100 Shuttle launches, so clearly most of the bugs have been worked out of the Soyuz system by now. The fact it's a far smaller rocket means less energy is required to launch it into orbit, reducing the stress and strain on the system and making it inherently safer than the Shuttles, with all that fuel and weight they have to contend with. There's also no reason to couple human payloads with equipment and supplies bound for orbit. In fact, it's downright senseless.
Here are some reliability figures for boosters in common use. With the exception of Soyuz, these are all unmanned boosters. Note that many of these unmanned boosters are as reliable (or even more reliable) than the Shuttle, which becomes a 2 billion dollar supersonic crematorium for all 7 astronauts aboard roughly 1 mission in 50:
Atlas 1&2 - 49 launch attempts, 95.9% reliability
Delta 2 - 73, 98.6%
Ariane 4 - 81, 96.3%
Proton - 254, 89.4%
Soyuz - 958, 99.3%
Long March - 54, 90.7%
Quite frankly, the Shuttle is nothing but a jobs program. Everything that's being done with the ISS could be done - cheaper and safer - using Russian launchers. For some interesting stats regarding launchers and costs, see this PDF file (sorry for the format, but it's informative), this NASA FAQ on launchers (it's from the mid-'90s, but still mostly accurate), and