AboutKenneth Renshaw Expertise Answer basic space flight questions, research info on specific space flights. Answer questions on astronomy
Experience Amateur astronomer and avid astronomy/space flight fan for 31 years.
Organizations Official NASA/JPL Solar System Ambassador for Arkansas and Missouri (one of about 300 nationwide). (http://www2.jpl.nasa.gov/ambassador/profiles/Kenneth_Renshaw.htm)
Question the deep space probe was an awesome spectacle and a testament to the people who designed and built it.
ok so NASA want to send a probe to Alpha Cent. do they take a map of the local star region then programme it into the probes computers?
i remember reading about polynesian voyagers who sailed the pacific using sun,moon,stars etc as reference points to help them navigate. would the same apply to interstellar navigation as reference points go?-------------------------
Followup To
Question -
Because of the vast distances of space how would a ship accurately navigate his way(from earth)to say alpha centauri or betelguese without getting lost on the way?
Answer -
Hi, thanks for writing! Let me use the Deep Impact spacecraft, which will hit a comet (Tempel I) this Monday morning, as an example. The probe will hit a 3 mile target at a staggering distance of 83 MILLION miles on the early morning (E USA time) of the 4th of July. The spacecraft travels very close to the correct path of the comet from the very beginning, and the comet is in the tracking cameras on a number of occasions enroute, with TCMs (trajectory correction maneuvers) firing rocket engines a few times to finetune the path, as the comet gets closer (and larger). At the last few hours, cameras onboard the probe will center a target on the tiny comet nucleus to hit. In summary, any rocket gets in the ballpark from the very beginning, with tracking and rocket firings taking place enroute to finetune the final path of the spacecraft. Unless there is a terrible computer or technical problem, any star can be gotten close to (the spacecraft won't get "lost"), and the final destination can be finetuned as the flight progresses. This finetuning will, of course, have to be automated, as communication between the earth and the spacecraft will take YEARS, even at the speed of light (a lot of the Deep Impact, about 6 light-MINUTES from earth, is automated). A similar analogy: Use a road atlas to get from California to New York, then stop and get a street map at the destination to fine tune your trip to the correct address. Write anytime!
Answer Hi! On the spacecraft are sensors that are locked on certain navigational stars. This keeps the spacecraft on track. The target is at a certain angle from the navigational star, and the spacecraft aims toward that angle, and thus reaches its target. It's similar to the ancient voyagers. Write anytime!
