Calculations show Iran's 2 February launch used beefed-up rocket
likely that it really is a two-stage rocket,” Geoffrey Forden of MIT told New Scientist. Forden analyzes the rocket programs of Iran and other countries, including China and Russia.
Fuel is key
David Wright of the Union of Concerned Scientists in Cambridge,
Massachusetts, has posted the results of his calculations (pdf) on line. For the calculations, Wright relied on the size and mass of Safir-2 reported in the Iranian media, which gave it a length of 22 meters, a diameter of 1.25 meters, and a mass of 26 tons. He also determined the relative sizes of the two stages from photos of the rocket posted on line. Given the rocket’s volume, its reported mass is consistent with a type of hydrazine called UDMH, which has long been used by China in its space launch vehicles, Wright says.
Assuming the fuel had the efficiency of UDMH, Wright also calculated the rocket’s thrust and specific impulse, a measure of how much momentum a rocket can provide per kilogram of fuel burned. The calculated figures are enough to give a payload like Omid a speed of 7.6 kilometers per second at an altitude of 240 kilometers, which is about right for the orbit Omid is observed to be in. “I don’t know for sure that that’s what they did, but [this] would seem to give Iran the capability to do this with two stages, and the reports coming out of Iran all seem to be pretty definite that it was two stages,” Wright said.
If Iran has developed more advanced rockets that can burn more efficient fuel, then it is a step closer to launching people into space, Forden says. Reza Taghipour, head of Iran’s Aerospace Industries Organization, has said this is a goal Iran hopes to achieve. The Long March rockets that China uses to put its taikonauts in orbit burn UDMH, although these are much larger and more powerful than the Safir-2. “[Iran] could get a person up into low-Earth orbit certainly within a decade, at the rate they’re going,” Forden says. “Whether or not the guy can return safely is another question. A lot of things have to go right.”
Most countries are worried about Iran’s rocket program because the more advanced and powerful these rockets are, the more capable they are of carrying the nuclear weapons. Iran’s nuclear weapons programs have been accelerating and experts now estimate that within twelve month Iran will have sufficient amounts of fissile material for its first nuclear explosive device.
If Iran has developed a more efficient launch vehicle, the concerns about Iran’s nuclear break out will grow. “A three-stage vehicle could never really lift a nuclear warhead very far,” Forden says. “But you can use this two-stage vehicle with more powerful fuel to lift a nuclear warhead farther.” Europe would be within range of missiles launched from Iran either way, he says.
Note that even if it used the more advanced fuel, the Safir-2 that launched Omid would have been operating at its limits, and could not carry a nuclear warhead as far as the US, Wright says.
