Quotulatiousness

April 28, 2011

Learning from mistakes, Martian style

Filed under: Space, Technology — Tags: , , , — Nicholas @ 08:56

I have to admit it’s doubly amusing finding articles like Mars ate my spacecraft!, once for the content and once for the amusing title:

The investigation board made the not-terribly-earth-shaking observation that tired people make mistakes. The contractor used excessive overtime to meet an ambitious schedule. Mars is tough on schedules. Slip by just one day past the end of the launch window and the mission must idle for two years. In some businesses we can dicker with the boss over the due date, but you just can’t negotiate with planetary geometries.

[. . .]

NASA’s mantra is to test like you fly, fly what you tested. Yet no impact test of a running, powered, DS2 system ever occurred. Though planned, these were deleted midway through the project due to schedule considerations. Two possible reasons were found for Deep Space 2′s twin flops: electronics failure in the high-g impact, and ionization around the antenna after the impacts. Strangely, the antenna was never tested in a simulation of Mar’s 6 torr atmosphere.

While the DS2 probes were slamming into the Red Planet things weren’t going much better on MPL. The investigation board believes the landing legs deployed when the spacecraft was 1,500 meters high, as designed. Three sensors, one per leg, signal a successful touchdown, causing the code to turn the descent engine off. Engineers knew that when the legs deployed these sensors could experience a transient, giving a false “down” reading… but somehow forgot to inform the firmware people. The glitch was latched; at 40 meters altitude the code started looking at the data, saw the false readings, and faithfully switched off the engine.

A pre-launch system test failed to detect the problem because the sensors were miswired. After correcting the wiring error the test was never repeated.

H/T to Paula Lieberman for the link.

April 21, 2011

Elon’s Dragon may “land on Mars”

Filed under: Space, Technology — Tags: , , — Nicholas @ 12:35

While you’re talking up your own private space venture, you can probably be excused for a bit of boasting:

Famous upstart startup rocket company SpaceX, bankrolled and helmed by renowned internet nerdwealth hecamillionaire Elon Musk, has once again sent its goalposts racing ahead of its rapidly-advancing corporate reality.

The plucky challenger has stated that its “Dragon” capsule is not merely capable of delivering supplies to the International Space Station: it is — potentially — also capable of carrying astronauts to the space station and back down to Earth again.

In a statement released yesterday, Musk and SpaceX also make the bold claim that the Dragon, once fitted with modifications that the company is now developing under NASA contract, would also be able to land “almost anywhere on Earth or another planet with pinpoint accuracy, overcoming the limitation of a winged architecture that works only in Earth’s atmosphere” (our emphasis).

October 14, 2009

Neuter NASA to save manned space exploration?

Filed under: Economics, Space, Technology — Tags: , , — Nicholas @ 12:14

Gregg Easterbrook, to be polite, isn’t a fan of NASA’s big-budget plans:

Soon, Barack Obama must make a decision on whether to continue funding NASA’s daffy plan to build a Motel 6 on the moon. The president will be put on the spot when the final report of a space commission [. . .] is delivered. Rumor is that in keeping with the tradition of Washington commissions, the report will contain extremely vague language about sweeping reform; then cite every item on every wish list of every interest group with a finger in this pie; then recommend nothing specific, so as to offend no interest group; then close with a call for higher subsidies. NASA is not one of the core missions of government, and spends only one-half of 1 percent of the federal budget, so space waste is relatively minor in the scheme of things. But if public policy can’t get this right, what can it get right?

Right now NASA’s budget is $18 billion annually, and the quarter or so spent on science — planetary probes, telescopes that scan the far universe — is going very well. The rest of NASA is a mess. The agency has just thrown $100 billion of your money down the drain on the space station, which has no scientific achievement and no known purpose other than keeping checks in the mail to favored contractors and congressional districts. The station is such a white elephant the current plan is to “deorbit” the thing in 2016. “Deorbit” is polite for “make it burn up in the atmosphere.” So after spending $100 billion to build a space station, we’ll destroy it. Your tax dollars at play!

Since 2004, NASA has said its next goal is a manned outpost on the moon, as a stepping-stone to manned travel to Mars. There’s nothing a person could do on the airless, lifeless lunar surface that a tele-robot operated from a Houston office building could not do at a fraction of the price and risk. And the moon has nothing to do with Mars. Any Mars-bound mission will leave directly from low-Earth orbit to the Red Planet: stopping at the moon, then blasting off again, would consume the mission’s fuel to accomplish nothing. Though NASA has been studying moon-base and Mars-mission proposals for five years, the agency refuses to give a cost estimate — a sure sign the plans cannot pass a giggle test. Considering the space station price was $100 billion for a limited facility that was not accelerated to the speed necessary to reach the moon — speed means fuel which means higher price — even a Spartan moon base easily could cost several hundred billion dollars. For what? Why, for “economic expansion”! Today, no one is interested in economic expansion at Earth’s poles, which are far more amenable to life than the moon, have copious resources, and can be reached at one-ten thousandth the cost of reaching the moon.

There’s a lot more, buried in the middle of his weekly “Tuesday Morning Quarterback” column at ESPN.com. The numbers for manned exploration of Mars aren’t encouraging, either.

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