Like many other desirable things not included in the Constitution, "informational privacy" seems like a good idea – wherefore the People have enacted laws at the federal level and in the states restricting the government’s collection and use of information. But it is up to the People to enact those laws, to shape them, and, when they think it appropriate, to repeal them. A federal constitutional right to "informational privacy" does not exist.This disagreement by necessity turns on interpretation, because the Constitution simply doesn't address the matter (the word privacy does not appear anywhere within the text of the Constitution or its amendments). Some state governments and many privacy advocates consider this to be a serious deficiency, and aside from federal laws enacted to protect the privacy of personal information in a variety of contexts, 10 states have individual rights to privacy explicitly conferred in their state constitutions.
The reliance on Whalen seems somewhat insufficient, since in that case the court said that the duty of the government to avoid unauthorized disclosure of personal information that could be harmful or embarrassing to the individual "arguably has its roots in the Constitution." In the current case, there is no dispute that NASA, as a federal government agency, is restricted under the Privacy Act (5 USC §522a) to limit the personal information it collects to only what is necessary to accomplish the intended purpose (in this case, to perform a background check) and from disclosing personal information it collects or for using it in any way inconsistent with the purpose for which it was collected. Given these protections regarding personally identifiable information collected on contractors and other individuals subject to background investigations, the only real question is whether the information sought on prior drug use and treatment go beyond what is reasonable or necessary for the government to ask in order to determine if the individuals are sufficiently trustworthy to perform the tasks their contract entails. It seems hard to argue that information about prior illegal activities, especially those involving potential addictions, would not be relevant to making a determination of trustworthiness. If so, then there is really no reason to entertain a debate about whether individual privacy rights are or are not afforded by the Constitution, although exposing the difference of opinion among Supreme Court justices offers some indication that the outcome of future cases that come before the Court on this issue might be hard to predict.