Tuesday, February 10, 2009

Is Iran's space programme more advanced than thought? - space - 09 February 2009 - New Scientist

 

Iran's first satellite launch aboard a home-grown rocket last week has left observers puzzled over just how it was done. Was the satellite launched by a feeble rocket pushed to its limits, or has Iran's secretive space programme managed to develop a far more powerful launch vehicle without anyone noticing? The answer will affect how soon the country might achieve its stated goal of sending humans into space.

Iran launched its satellite – called Omid, or "Hope" – on 2 February. According to Iranian media, it is a 40-centimetre cube weighing 25-kilograms, and is equipped with radio transmitters.

Foreign tracking stations and amateur sky watchers have been following the craft's relatively low orbit, which is expected to decay over weeks or months due to atmospheric drag.

At first, it was thought that the launch vehicle, called Safir-2, was derived from relatively feeble missiles that burn ambient-temperature liquid fuel, which Iran was already known to have.

Two of these missiles stacked one on top of the other could boost a third, small, solid-fuel rocket that could take a lightweight payload like Omid to orbit.

Two stages

But evidence has begun to emerge that the rocket might be more powerful than this. Amateur observers report that the last stage of the rocket, which is also in orbit, is much brighter than the satellite itself, suggesting it is too large to be the third stage of a relatively modest rocket.

Geoffrey Forden of MIT, who specialises in the analysis of foreign countries' launch capabilities, is one of those now mulling over whether the rocket had just two stages, with a second stage that was much more powerful than anything Iran was known to possess. This would be possible using a cryogenic fuel system involving liquid oxygen.

If true, this would have important implications for Iran's ambition to launch astronauts into space, something Reza Taghipour, head of Iran's Aerospace Industries Organization, has said the country hopes to do before 2021.

Suborbital flights

"If they used three stages, there's no way they're going to be getting a man to space anytime soon," Forden says. "If it's two stages, then maybe they could have suborbital flights fairly soon."

Ongoing tracking of the final stage's orbit should help to provide an answer. That's because the speed of the object's drop due to atmospheric drag will provide clues as to its size.

Either way, the launch has heightened concern among those nations that suspect Iran is trying to develop nuclear weapons.

Military concerns

A rocket that can put a few dozen kilograms in orbit can also deliver a few hundred kilograms – the mass of a nuclear warhead – as far as western Europe. Iran says its satellite launch was for peaceful purposes.

"It would be very difficult for the spacefaring nations to say that Iran doesn't have a sovereign right for space launch capabilities," says Joan Johnson-Freese of the US Naval War College in Newport, Rhode Island.

"They have a very legitimate reason for wanting to be able to launch their own satellites for both economic and prestige reasons, but it also gives them an additional military capability," she told New Scientist. "The dual-use aspect really puts you in a dilemma."

If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.

Is Iran's space programme more advanced than thought? - space - 09 February 2009 - New Scientist

No comments: