posted 06-27-2008 02:57 AM               

Two Russian cosmonauts on the international space station practiced Thursday for a dramatic spacewalk planned next month, which will involve taking an explosive bolt from the exterior of a docked Soyuz spacecraft and bringing it into the station itself.

The risky operation is aimed at figuring out why similar bolts on earlier Soyuz spaceships misfired, leading to two rugged, off-course landings over the past year. The cosmonauts hope to avoid similar problems when they use the currently docked Soyuz to return to Earth at the end of their mission in October.

One of the most delicate aspects of the July 10 spacewalk will be handling the bolt, which sources say packs twice the explosive force of an M-80 firecracker when ignited.

posted 06-27-2008 05:13 PM               

Made one heck of a splash when I threw it overboard and one heck of a splash when it blew!

posted 06-27-2008 05:24 PM               

quote:

---

Originally posted by ejectr:
I once waltzed a live 5" projectile down a 5" 38 cal gun mount ladder with a ticking 35 second fuse after a hang fire.

---

A hang fire in a 5" 38?? Man you are seriously dating yourself!!! :-) Former Gunnersmate?

posted 06-27-2008 08:23 PM               

quote:

---

Originally posted by LCDR Scott Schneeweis:
A hang fire in a 5" 38?? Man you are seriously dating yourself!!! :-) Former Gunnersmate?

---

Actually...I'm dating myself even worse. It was a 5" 54, not a 5" 38.

posted 06-28-2008 01:41 AM               

Also, I have to wonder if NASA might want to reconsider overriding the Navy's request to hold back any possible astronaut candidates currently operating in an EOD capacity from consideration.

posted 06-28-2008 06:24 AM               

I know I was adding up my insurance policies as I counted off the seconds in my mind when the thing WOULD blow. Sometimes not knowing if it WILL blow is worse than knowing WHEN.

posted 07-09-2008 06:03 AM               

Russian Spacewalk to Retrieve Soyuz Pyro Bolt

International Space Station (ISS) Expedition 17 commander Sergei Volkov and flight engineer Oleg Kononenko will inspect and retrieve an explosive bolt from the Soyuz TMA-12 spacecraft during a July 10 spacewalk. The bolt will be returned to Earth for examination.

The spacewalk comes in the wake of two consecutive ballistic entries by the previous Soyuz, entries that resulted in high-G rides for the crews and landings hundreds of miles short of the planned recovery area. Russian engineers say they have evidence that failed explosive bolts that help separate two modules likely are responsible.

Scheduled to begin at about 1:20 p.m. CDT, the spacewalk should last about six hours and focus on the area between the Soyuz return and propulsion modules.

Volkov and Kononenko will leave the Pirs docking compartment and move to the Strela hand-powered crane mounted nearby. Volkov, wearing the red-striped Orlan spacesuit and designated EV1, and Kononenko will mount a foot restraint on the end of Strela.

Kononenko, EV2 in the blue-striped suit, will get into the foot restraint and Volkov will maneuver him to the Soyuz, docked to the Earth-facing port on Pirs.

After installing covers to protect nearby thrusters, Kononenko will cut and secure insulation and inspect and photograph the area. Then Volkov will move along the Strela to join Kononenko, who will install a handrail on the Soyuz and a cover to protect fluid lines.

Work Ares 1

Volkov will cut a wire tie between adjacent pyrotechnic bolts in the suspect position and demate an electrical connector. Next he will unscrew and retrieve the pyro bolt and stow it in a protective cylindrical case. He'll reinstall the insulation cover, and remove the thruster covers, taking photos after each step.

Work Ares 2

Kononenko and Volkov will move back to the Strela controls and both will maneuver the crane back to its stowage position on Pirs. They'll stow a bag with the blast-proof container holding the pyro bolt back in the airlock.

Work Ares 3

If time permits, they'll install a docking target on the space-facing side of the Zvezda service module. It will help with the docking of a Russian mini-research module atop Zvezda. The module will be delivered on a future mission.

The cosmonauts will return to Pirs, enter the airlock and close the hatch.

Flight engineer Greg Chamitoff will remain in the Soyuz during the spacewalk, part of contingency preparations for the unlikely event the Pirs airlock cannot be repressurized.

Volkov and Kononenko will conduct another spacewalk July 15 to outfit the Russian segment's exterior, install one scientific experiment and retrieve another.

posted 07-09-2008 01:52 PM               

But, if I were a Cosmonaut on the ISS right now the day before this spacewalk, I would be regretting the fact there is apparently no vodka onboard. This the type of thing that would make me, a stone cold sober guy, want to at least have a stiff drink or two the night before doing (not enough to get drunk and screw up my reflexes for the next day, just enough to get a slight buzz).

posted 07-09-2008 04:03 PM               

quote:

---

Originally posted by Jay Chladek:
This could very well be the most critical EVA ever performed, because it isn't about just fixing hardware. It is about fixing your ride home.

---

posted 07-10-2008 07:59 AM               

quote:

---

Originally posted by music_space:
On which mission? And reinstalled when?

---

posted 07-10-2008 08:05 AM               

"The spacewalk is unusual. You can bet the crew will be very deliberate," said former NASA astronaut Tom Jones, an aerospace consultant who has participated in three spacewalks outside the space station. "But the added risk is probably not greater than the risk of the spacewalk itself."

Explosive bolts have been used extensively on spacecraft, including NASA's manned shuttle, and on military aircraft for decades while accruing a good safety record, said Arthur Draut, a professor of aeronautical sciences at the Embry-Riddle Aeronautical University in Prescott, Ariz.

"The technology is mature enough that handling the bolt is fairly safe," Draut said. "I don't see any danger from removing it."

posted 07-10-2008 12:30 PM               

quote:

---

Originally posted by Lou Chinal:
"throw it over the side"

---

Of potential greater risk to the crew will be the large knife they will use to cut away insulation during the EVA. Never has such a large blade been deployed during a spacewalk.

posted 07-10-2008 01:41 PM               

quote:

---

Originally posted by Robert Pearlman:
Okay, let's put this into some perspective. Their Soyuz, as is, with no EVA or repair, is safe to reenter. A ballistic reentry, while not desirable, is one of the standard modes of return. They are doing the repair because they can, not because they must.

---

Okay, I understand that one bolt hanging up would still be safe enough for the Soyuz to come in ballistically as it would just rip off like it did on the last two TMA capsules. But what if a pair had a hangup (or something else)? As such if the Soyuz came in a little deeper like Soyuz 5 did, it could make for a nasty ride. Add a little more weight to the mix then Soyuz 5 (three crewmembers in a slightly heavier capsule compared to one) and something even more critical could be damaged in a front first ballistic reentry before the propulsion module rips off and the craft rights itself.

Granted I do see how the propulsion module is bolted to the descent module as they are using the same type of truss structure they've used on the R-7 rocket stages dating back to Vostok. And it looks as though these tubes will burn through or rip apart somewhat easily when sideways aerodynamic forces build up on a reentry. But throw a wild card into the mix and it could make for a rather bad day. As such, I don't think they are doing this JUST because they can, but rather so they can eliminate this one factor from the fault chain in case something else goes wrong.

posted 07-10-2008 11:06 PM               

The spacewalkers installed a thermal blanket over their work area, took photos of the site and then moved the Strela crane back to its stowage position on Pirs.

posted 07-12-2008 01:53 PM               

The EVA was successful!

My hat is off to Volkov & Kononenko.

I know you are right about the bolt, but I still worry.