About 17 percent of Alliants revenue is derived from the work it does for NASA under a multi-year contract that expires in 2007, Bitz said. The company expects to supply 74 of the reusable rocket motors by the time the contract runs out, and revenue Alliant expects to generate from the contract accounts for less than 20 percent of the firms total backlog of about $5.3 billion, he said.

Alliant also provides components for other launchers, including the Titan 4B and Delta 2, 3 and 4 rockets, and is a large supplier of ammunition to the military. The company also provides motors for various missile systems.

Alliant issued a statement Feb. 3 affirming its financial projections for the fiscal year that ends March 31 in response to a sharp drop in its stock that day. Alliant shares dropped $6.34, or more than 11 percent, Feb. 3, then rose $2.29, or nearly 5 percent, Feb. 4, to close at $50.31.

Bitz said the company is comfortable with the guidance it issued investors despite the uncertainty about future shuttle missions surrounding the loss of Columbia. "Given all the questions weve gotten from analysts and shareholders, we thought it was the prudent thing to do."

Even though Alliants work for NASA was not immediately affected by the Columbia disaster, it is not surprising that investors unloaded shares in the company in reaction to the tragedy, said Robert Friedman, senior aerospace and defense analyst for Standard & Poors in New York.

He said the companys stock appears to have been overvalued before it tumbled, giving even the suggestion of trouble ahead the power to trigger a sell-off. Moreover, the shuttle accident underscores the volatile and risky nature of the space business, and it may have reminded investors that such a large chunk of the companys revenue comes from a single source, Friedman said.

"You have to have very [conservative] long-term growth estimates to discount for the erratic nature of the space industry," he said. "You cant predict these things but you have to build them into your [calculations], especially with a relatively small outfit like Alliant."

Even as Alliant shares rose Feb. 4, another space hardware company whose revenues are even more dependent on the space shuttle continued to plummet. Shares of Spacehab Inc. of Webster, Texas, fell 5 cents, or 6 percent, Feb. 4, to close at 83 cents. On Feb. 3, Spacehab declined 10 cents, or more than 10 percent.

Spacehab manufactures modules that house experiments on shuttle missions. The companys Research Double Module, valued at about $100 million, was lost when Columbia disintegrated.

Officials of two major NASA contractors, Boeing Co. of Chicago and Lockheed Martin Corp. of Bethesda, Md., said their NASA-related work is continuing despite the Columbia accident. Boeing and Lockheed Martin also discounted the potential for any disruption to that work to significantly impact their overall financial results.

Lockheed Martin and Boeing jointly own United Space Alliance of Houston, which operates the shuttles under a multi-year contract with NASA.

"Were standing by NASA to support the investigation, but as far as the financial impact, the shuttle only accounts for about 3 percent of our sales," said Meghan Mariman, a Lockheed Martin spokeswoman. "Day to day, our first priority is assisting NASA, but things are continuing as normal."

Lockheed Martins work for NASA includes supplying the external tank that is suspected of contributing to Columbias breakup as it reentered the atmosphere. Ron Meder, a spokesman for the companys space operations unit in Houston, said NASA has sent investigators to Lockheed Martins tank-manufacturing plant in Louisiana, but the company continues to perform work for NASA under its contract with the space agency.

Boeing spokeswoman Anne Eisele said her company considers the roughly $2 billion in annual revenue it derives from the space shuttle program to be "a very important part of our business" even though that amount accounts for only about 3 percent of Boeings overall annual sales. "Its premature to speculate on the specific business impact, which presumably would be affected by the length of the investigation."

One industry source familiar with Boeings NASA-related activities said the companys long-term health is likely to be largely unaffected by the shuttle disaster and could even come out ahead. Boeing stands to gain if policymakers accelerate work on a next-generation launcher to supplant the space shuttle program in response to the accident, and the firm would be in a good position to build a new shuttle if the government decides to take that approach, this source said.

Boeings stock price was affected only modestly as invested to the shuttle tragedy. The aerospace firm slipped 48 cents, or about 1.5 percent Feb. 3, then rose 13 cents, or less than half a percent, Feb. 4, closing at $31.24 per share.

Lockheed Martins stock price was more fluid in the two trading days since Columbia was lost. The companys shares lost almost 3 percent of their value Feb. 3, dropping $1.50 to $49.55. The companys share price rose almost 3.5 percent Feb. 4, gaining $1.72 to close at $51.27.