Could an astronaut use their cellphone in outer space?

[Shagnasty]

Of course you can use a cell phone in space. What you can use it for is a different story.

[Markxxx]

The real question is if you talk into a cell phone and there’s no tower around to allow other people to hear you, do you make a noise?

[Giles]

So, this documentary, in which an astronaut uses her cell phone to send email from the vicinity of Alpha Centauri got this detail wrong? (It did get the time delay right: to send and receive an email takes a bit over 8 years.)

[Derleth]

What about using GPS in space? There’s probably no practical reason to, but if someone did take a GPS receiver into, say, the Space Shuttle’s usual orbit with them would it work in space?

[GreasyJack]

@Keeve

Am I the only one who remembers the cell phone calls made from American Airlines Flight 77 on September 11?

According to Wikipedia:My interpretation of this is that they descended through 2200 feet only a minute or so before the crash. That means those calls must have been made at a much higher altitude, though I can’t say how much.

That same Wikipedia page shows one call made at 9:12 AM, and the other between 9:16 and 9:26. The crash occurred at 9:37, so it is quite possible that they were still pretty high up.

I was under the impression that most of these were made with those old seat-back pay phone things, which didn’t operate on a cell-phone network.

[Chronos]

GPS can be and is used in space. It can be very practical to know precisely what the parameters are of one’s orbit.

[Derleth]

@Chronos

GPS can be and is used in space. It can be very practical to know precisely what the parameters are of one’s orbit.

OK. I thought they relied more on Newtonian dead reckoning and position relative to Earth stations.

Can you get usable GPS signals if you’re farther out from the Earth than the GPS constellation is?

[Rhythmdvl]

Recalculating…

[Stranger_On_A_Train]

@Derleth

OK. I thought they relied more on Newtonian dead reckoning and position relative to Earth stations.

Can you get usable GPS signals if you’re farther out from the Earth than the GPS constellation is?

Historically rockets and ballistic missiles have used inertial navigation (which is close enough to “dead reckoning” for discussion purposes) with correction via stellar orientation or (in some very early systems like Titan I) ground radio tracking. Most modern space launch vehicles and some guided sounding rockets use a combination of inertial navigation and GPS (integrated GPS/INS). Since GPS satellites are at about 15000 nmi altitude, this is feasible for LEO space vehicles. Above that, inertial navigation, TDRSS, or the Deep Space Network (DSN).

Stranger

[SciFiSam]

@engineer_comp_geek

This is correct. Cell phones use towers, and the antennas on those towers are directional. They send and receive best in the plane along the surface of the earth. The farther up the signal is tilted (as it would be if you are in an aircraft) the more the signals are attenuated, so the cell phone tower gets less and less able to send and receive the higher you are in relationship to it.

You’d have to change out the antennas to make them less directional if you want them to work in the “up” direction. You’d also have to add a lot more towers, since you’ve only got so much signal to work with, and if you are radiating it out in all directions that means there’s less available to go in the “flat” direction when you start sending some of the signal “up”. You’d reduce the range of all of the existing towers and end up with gaps in coverage that would need to be filled with more towers.

Yes, but only up to about 5,000 feet or so. After that, your ability to connect drops off fairly quickly. Between 5,000 and 10,000 feet you might get a signal, and might not, with your chances decreasing the higher you go. Above 10,000 feet getting a connection is going to be almost impossible.

Most spacecraft go above 10,000 feet (and the ones that don’t usually have bigger problems than whether or not their cell phones work), so cell phones are going to be a problem for them.

Planet earth is blue and there’s nothing I can do…

Rapid switching between towers has never really been much of a problem. The problem with early systems was that you could reach not only multiple towers, but multiple systems when you were up higher. This really wreaked havoc with the early cell phone systems. Cell phone users are incredibly obnoxious though. It often seems like the best way to guarantee that someone will use a cell phone in a particular location is to put a sign there saying cell phones can’t be used. Tell people that cell phones will cause their plane to crash and they still insist on using them. I think there’s some sort of Darwinian lesson in there somewhere. Anyway, because cell phone users are so obnoxious, the cell phone companies have just had to cope with it, and now the systems are all robust enough to handle cell phones in planes.

If all of the problems are fixed, then why don’t we allow them on planes now? It’s not just a holdover from an earlier time. The FCC still doesn’t allow them mostly for two reasons. The first is that an airborne cell phone will contact multiple towers, which means it will tie up communication channels in several towers simultaneously, reducing the number of channels available for other people to use, and the FCC doesn’t like wasting bandwidth. The second reason is that cell phones absolutely do interfere with airplane equipment, mostly communication equipment. In some cases they have interfered with the pilot’s ability to contact the tower and have also occasionally caused problems with navigation equipment. According to the pilots I have talked to, cell phones mostly show up as noise in their headsets, which is mostly just an annoyance, but can make it harder for them to hear instructions from the tower. The FAA doesn’t allow cell phones on planes either, for the same reason.

I don’t fly often, but the last time I did, between London and Rome in about 2008, mobile phones were permitted and worked well. I’ve received calls and Facebook messages and tweets from many people on planes since then.

[Ximenean]

As I understand it, when airlines offer in-flight cell phone service they actually have a mini base station on board, in effect, which integrates with the regular cell phone network via satellite. So your phone is communicating with that, not with towers on the ground.

[Dereknocue67]

Of course you can use your cell phone to communicate in outer space. If you’re angry at your fellow astronaut, you can throw it at them. Other than that, you’ve got yourself a weightless paperweight.

[Rhythmdvl]

@Dereknocue67

Of course you can use your cell phone to communicate in outer space. If you’re angry at your fellow astronaut, you can throw it at them. Other than that, you’ve got yourself a weightless paperweight.

…that plays Angry Birds.

[Gyrate]

@Rhythmdvl

…that plays Angry Birds.

Will the birds be going after the Piiiiiigs Iiiiiin Spaaaaaaaaaace?

[Richard_Pearse]

@Ximenean

As I understand it, when airlines offer in-flight cell phone service they actually have a mini base station on board, in effect, which integrates with the regular cell phone network via satellite. So your phone is communicating with that, not with towers on the ground.

Yes, that would be the case with SciFiSam. When I’ve used a cell phone airborne it has been direct to a ground cell tower and was at around 10,000’ and about 30nm from the nearest tower which is consistant with engineer_comp_geek’s comments.

[Ken001]

Well…call me simple but I thought the OP’s question was whether cellphones could send and receive in space? Given that soundwaves cannot be transmitted in space (Noone can hear you yadda yadda :D)

In answer to my simple version: Yes. Cellphones send and receive radio waves which travel more happily in a vacuum that in our atmosphere. Admittedly the sound from the earpiece would need to be wired into the helmet to work.

[Shirley_Ujest]

@SciFiSam

I don’t fly often, but the last time I did, between London and Rome in about 2008, mobile phones were permitted and worked well. I’ve received calls and Facebook messages and tweets from many people on planes since then.

Did you have huge roaming charges? Or is there a All-Europe included plan, like here in the states for Just About Every Corner of the 48 Contiguous States (except the 4 sq. mile area around Shirley Ujest’s House.)

[Shirley_Ujest]

@Shagnasty

Of course you can use a cell phone in space. What you can use it for is a different story.

Ima gonna use my cellphone to throw it at your head. and I don’t need an app for that.

[Tim_T-Bonham.net]

@engineer_comp_geek

If all of the problems are fixed, then why don’t we allow them on planes now? It’s not just a holdover from an earlier time. The FCC still doesn’t allow them mostly for two reasons. The first is that an airborne cell phone will contact multiple towers, which means it will tie up communication channels in several towers simultaneously, reducing the number of channels available for other people to use, and the FCC doesn’t like wasting bandwidth. The second reason is that cell phones absolutely do interfere with airplane equipment, mostly communication equipment. In some cases they have interfered with the pilot’s ability to contact the tower and have also occasionally caused problems with navigation equipment. According to the pilots I have talked to, cell phones mostly show up as noise in their headsets, which is mostly just an annoyance, but can make it harder for them to hear instructions from the tower. The FAA doesn’t allow cell phones on planes either, for the same reason.

And the airlines don’t allow them for a third reason: it would cut into the big profits they make from those expensive seat-back telephones.

[Tim_T-Bonham.net]

There is also the matter of cost.

Shipping anything up to the Space Station costs about $120 per pound ($2.70/kg). So just getting a cellphone up there is expensive.

And given the huge roaming charges the cell phone companies charge for being just a bit out of their area, can you imagine the outrageous amounts they would bill for a call from outer space?